There are known fuselage mounted undercarriages comprising landing gear which can be retracted into the landing gear bay after takeoff and extended for landing purposes. Typically these arrangements include damping means and a collapsible side brace or jack powered by an actuator for providing the retraction and extension motion of the landing gear. There are many types of landing gear that fall within this general description, each being designed to meet differing constraints. Among these constraints are the shape of the fuselage, the available anchor points for the landing gear, the weight of the aircraft, its capacity and the type of duty to which it is subjected.
Several known construction attempt to minimize the volume that the undercarriage occupies in its retracted position in the storage bay.
Examples of this construction are provided by U.S. Pat. No. 4,189,117 to Masclet et al., wherein a hydraulic maneuvering and wind bracing jack is provided for controlling the extended and retracted positions of the landing gear. The jack provides a single means of lowering and retracting the undercarriage, and it is mounted so as to minimize the required storage bay height.
U.S. Pat. No. 4,199,119 discloses a hydraulic retraction jack pivoted on the undercarriage leg casing and fixed to the aircraft for lifting and extending the landing gear. A rod of fixed length having one end fixed to the wing is mounted at its other end via a lever to the shock absorber so as to cause shortening of the undercarriage upon retraction, thus reducing the required storage bay length.
U.S. Pat. No. 4,433,820 discloses a jack for collapsing a side brace which supports the undercarriage so as to enable retraction and extension thereof during take-off and landing. By virtue of parallel pivot axes for the jack and the undercarriage, the volume occupied by the retracted undercarriage is of minimal thickness.
The problem with all of the above systems is that because they use an actuator which is external to the landing gear for retracting it, the external actuator occupies a lot of storage bay space.
Therefore, it would be desirable to provide a landing gear construction which minimizes the space required in the storage bay.